Various types of carbamate and carbamate ester insecticides have previously been described. For example, U.S. Pat. No. 3,997,549 to Fukuto and Black discloses N-aryl-sulfenylated derivatives of benzofuranyl methylcarbamates as effective pesticides. U.S. Pat. No. 4,006,231 to Black and Fukuto discloses N-aminosulfenylated derivatives of carbofuran as effective pesticides; U.S. Pat. No. 3,843,689 to Brown discloses production of N-methyl- or N-phenyldithiocarbamates produced from N-chlorothiocarbamates as insecticides; and U.S. Pat. No. 4,261,897 to Fahmy and Fukuto discloses production of N-chlorosulfinylcarbamate esters produced from carbamates as useful intermediates in the preparation of pesticides. In addition, U.S. Pat. Nos. 4,262,015 and 4,263,318 to Fahmy and Fukuto disclose N-alkylthio- and N-arylthiosulfinylcarbamate esters, and N-alkoxy- and N-aryloxysulfinylcarbamate esters, respectively, as insecticides. Further, amidothioate ester insecticides are described in U.S. Pat. No. 4,279,897 to Fahmy and Fukuto, and thiomethyl carbamate pesticides are disclosed in U.S. Pat. No. 4,081,536 to Nelson. U.S. Pat. No. 4,006,231 to Black and Fukuto discloses N-aminosulfenylated derivatives of carbofuran and U.S. Pat. No. 3,843,689 to Brown and Kohn describes the production of N-chlorothio-carbamates useful in the production of pesticides.
In accordance with the present invention, a novel class of carbamate compounds is provided, the compounds being effective as pesticides. More particularly, the compounds are generally N-phosphinoaminosulfinylcarbamate esters which are useful as insecticides and are prepared by reacting on N-chlorosulfinylcarbamate esters with phosphoramidates or phosphoramidothioates, using a hydrogen chloride acceptor such as pyridine either in the presence or absence of a suitable organic solvent.
The resulting compounds of the invention are highly effective against certain pests and insects, and have substantially reduced mammalian toxicity, e.g., as compared to other potent carbamate insecticides such as carbofuran, described in U.S. Pat. No. 3,474,171. Thus, the invention compounds, while having high toxicity toward certain pests or insects, are relatively safe to mammals.
In the following detailed description, all temperatures are intended as having been expressed in degrees centigrade, unless otherwise indicated by the context of the specification.